"Alice Gear Aegis: Doki! Actress Darake no Mermaid Grand Prix" is a spin-off anime series based on the mobile game "Alice Gear Aegis." The story is set in a futuristic world where humanity faces threats from alien mechanical beings known as Vice. To combat these threats, humanity relies on Actresses, young women equipped with specialized combat suits called Alice Gear. The series focuses on a lighthearted and comedic take on the franchise, centering around a group of Actresses participating in a competitive underwater racing event called the Mermaid Grand Prix.

The narrative revolves around the protagonist, Misaki Suzuhiro, a cheerful and determined Actress who dreams of winning the Mermaid Grand Prix. Misaki is joined by her friends and fellow Actresses, including the calm and collected Yotsuyu Hirasaka, the energetic and competitive Rin Namiki, and the reserved yet skilled Fumika Momoshina. Together, they form a team to compete in the Grand Prix, which combines high-speed underwater racing with combat elements, as participants must navigate treacherous courses while fending off Vice attacks.

The series explores the dynamics between the characters as they train, strategize, and face challenges both on and off the racecourse. Misaki’s unwavering optimism and leadership inspire her teammates, while each character’s unique personality and skills contribute to their collective success. The story balances action-packed racing sequences with moments of camaraderie and humor, highlighting the bonds formed between the Actresses as they work toward their shared goal.

Throughout the series, the Actresses encounter rival teams, each with their own motivations and strategies, adding tension and excitement to the competition. The Mermaid Grand Prix serves as a backdrop for character development, as the Actresses confront their fears, insecurities, and personal growth while striving to prove themselves in the high-stakes event. The narrative maintains a light and entertaining tone, emphasizing teamwork, perseverance, and the thrill of competition within the vibrant and futuristic world of "Alice Gear Aegis."